Recording tape cartridge

ABSTRACT

A recording tape cartridge which enables size reduction of a drive device and is resistant to removal of a leader pin from a holding position in a case during non-use. In this cartridge, a recording tape is wound onto a single reel. The case is substantially rectangular, is formed by joining an upper case and a lower case, and rotatably accommodates the reel. The leader pin is attached to a tape end portion. A covering member opens and closes an opening for drawing out the leader pin. The opening is formed by cutting away a drive device loading side corner portion of the case. Joining portions for joining the upper and lower cases are provided at both ends of the opening. Holding portions which hold the leader pin are provided at inner faces of the upper and lower cases, on or inward of an imaginary line joining these joining portions.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a recording tape cartridge whichrotatably accommodates in a case a single reel onto which a recordingtape such as a magnetic tape or the like is wound, and is principallyutilized as a recording/replaying medium for computers and the like.

2. Description of the Related Art

Magnetic tape cartridges which accommodate in a case a single reel ontowhich a magnetic tape is wound, and which are principally utilized as arecording/replaying medium for computers and the like, have been knownin the prior art. A leader member, which is to say a leader pin, aleader tape, a leader block or the like, is provided at a distal end ofsuch a magnetic tape. The leader member is drawn out through an openingaperture of the magnetic tape cartridge by drawing-out means provided ata drive device side. Thence, the magnetic tape to which the leadermember is fixed is wound around a drive device side winding reel.

A reel gear is formed in an annular shape at the middle of a lower faceof the reel, and is exposed through an opening hole formed in a lowerface of the magnetic tape cartridge. A driving gear provided at a drivedevice side rotation shaft meshes with the reel gear. Thus, in thisstructure, the reel is driven to rotate. Consequently, the reel of themagnetic tape cartridge and the winding reel of the drive device arerotated contemporaneously. Hence, data can be recorded to the magnetictape, and data recorded at the magnetic tape can be replayed.

Such magnetic tape cartridges can be kept in a small accommodation spaceat a time of storage, and can record large volumes of information. Asshown in FIGS. 12 to 14, the position of the opening aperture, and thetype of a door that opens and closes the opening aperture is differentfor each of the different types of leader member. Specifically, in thecase of a leader pin 110, as shown in FIG. 12, an opening 118 is formedin a side wall 114 of a case 112. The side wall 114 is parallel with aloading direction into a drive device (the direction of an arrow P). Theopening 118 is opened and closed by a door 116, which slides to move inthe same direction as the loading direction.

However, if the opening 118 is provided in the side wall 114 of the case112 in this manner, the drive device side drawing-out means must turnthe leader pin 110 around from a left-right transverse direction of thecase 112 to draw out the leader pin 110. Therefore, a space for thedrawing-out means to turn around must be reserved at the drive deviceside, and a mechanism for turning around of the drawing-out means iscomplicated. Thus, the drive device will become larger, which isdisadvantageous. Moreover, there is a further problem in that adrawing-out path of a magnetic tape 111 becomes longer.

In addition, when the magnetic tape cartridge is not in use (not loadedin the drive device), the leader pin 110 is simply anchored and held byupper and lower ends thereof at recessed anchor portions 117, which areprovided by reducing the case thickness at parts of upper and lowervicinity peripheral portions which form the opening 118. Consequently,if, when the magnetic tape cartridge is dropped or the like, thevicinity of the opening 118 experiences an impact, these upper and lowervicinity peripheral portions may be deformed in a vertical direction,and the leader pin 110 may be displaced from the anchor portions 117,and may fall out.

Alternatively, in the case of a leader tape 120, as shown in FIG. 13, anopening 128 is formed in a front wall 124 of a case 122. The front wall124 intersects the direction of loading into the drive device (thedirection of arrow P). A door 126 opens and closes the opening 128. Thedoor 126 is a rotating-type door which rotates forward about a supportshaft 125 which supports the door 126 at a corner portion vicinity ofthe case 122. However, when the opening 128 is provided in the frontwall 124 of the case 122 in this manner, although there is no need fordrive device side drawing-out means to turn around, the door opensforward by a large amount. Therefore, it is necessary to reserve spaceat the drive device side, such that no part of the drive device impedesthe door 126 when the opening 128 is opened. Thus, the drive devicebecomes larger, and this is disadvantageous.

Furthermore, in the case of a leader block 130, as shown in FIG. 14, anopening 138 is formed by diagonally cutting away a corner portion 134 ata front side in the direction of loading into the drive device. Theopening 138 is directly opened and closed by the leader block 130.However, when the leader block 130 opens and closes the opening 138 inthis manner, there is a problem in that the leader block 130 will tendto become damaged or soiled. That is, the leader block 130 fits into adrive device side reel hub 136, and structures a portion of the reel hub136. Therefore, damage and soiling that would not be a problem for usualuse as a door make it difficult to fit the leader block 130 with thereel hub 136, and there is a risk that running of the magnetic tape 111may be disadvantaged.

Moreover, the leader block 130 is anchored only at peripheral portionsof the opening 138. Therefore, it is easy for the leader block 130 tocome out if the magnetic tape cartridge is dropped, which isdisadvantageous. In addition, the size of the leader block 130 is largein comparison to the leader pin 110. Therefore, there is a problem inthat constraints on the form of the case are numerous. Thus, the leaderpin 110, from which the function of the door is separated, is superiorto the leader block 130, which is combinedly used as the door.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide arecording tape cartridge which is provided with an opening aperture thatcan minimize length of a drawing out path of a recording tape, which canprovide for a reduction in size of a drive device, and which, when notin use, is less susceptible to removal of a leader pin from a holdingposition in a case, even when the vicinity of the opening aperture issubjected to an impact due to being dropped or the like.

In order to achieve the object described above, according to the presentinvention, there is provided a tape cartridge which is insertable at atape drive which carries out at least one of reading and writing of dataincludes: a case which includes a front wall portion facing in adirection of insertion of the cartridge, a side wall portionsubstantially parallel to the cartridge insertion direction, and anangled wall portion connected with the front wall portion and the sidewall portion and angled relative to the cartridge insertion direction,the case being structured by joining an upper case and a lower case at aplurality of joining portions; an openable and closeable tape accessopening provided at the angled wall portion of the case; and a leaderpin attached to a tape end, the leader pin being detachably held so asto be substantially vertical at a position which is on or at an innerside of a line from one to another of joining portions that are providedat vicinities of end portions, in plan view, of the tape access opening.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a recording tape cartridge.

FIG. 2 is a schematic exploded perspective view of the recording tapecartridge.

FIG. 3 is a schematic plan view of a lower case.

FIG. 4 is a schematic perspective view, viewed from above, showing adoor in a closed state of an opening.

FIG. 5 is a schematic perspective view, viewed from above, showing thedoor in an open state of the opening.

FIG. 6A is a schematic plan view showing a state during a transition ofthe door from the closed state of the opening to the open state.

FIG. 6B is a schematic plan view showing another state during thetransition of the door from the closed state of the opening to the openstate.

FIG. 6C is a schematic plan view showing yet another state during thetransition of the door from the closed state of the opening to the openstate.

FIG. 7 is an enlarged schematic perspective view of an opening apertureregion.

FIG. 8A is a schematic perspective view, viewed from above, showing avariant example of the door.

FIG. 8B is a schematic plan view showing the variant example of thedoor.

FIG. 9A is a schematic perspective view, viewed from above, showinganother variant example of the door.

FIG. 9B is a schematic plan view showing the other variant example ofthe door.

FIG. 10A is a schematic perspective view, viewed from above, showingstill another variant example of the door.

FIG. 10B is a schematic plan view showing the still another variantexample of the door.

FIG. 11A is a schematic perspective view, viewed from above, showing yetanother variant example of the door.

FIG. 11B is a schematic plan view showing the yet another variant of thedoor.

FIG. 12 is a schematic perspective view of a conventional magnetic tapecartridge equipped with a leader pin.

FIG. 13 is a schematic perspective view of a conventional magnetic tapecartridge equipped with a leader tape.

FIG. 14 is a schematic plan view of a conventional magnetic tapecartridge equipped with a leader block.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the accompanying drawings, an embodiment of the presentinvention will be explained. For the sake of convenience of explanation,a loading direction of the recording tape cartridge 10 into a drivedevice, which is shown as arrow A, is referred to as a forward direction(front side) of the recording tape cartridge 10, and the direction of anarrow B intersecting arrow A is a rightward direction. Firstly, generaloverall structure of the recording tape cartridge 10 will be explained.

[Overall Structure of Recording Tape Cartridge]

FIG. 1 shows a perspective view of overall structure of the recordingtape cartridge 10. FIG. 2 shows a schematic exploded perspective view ofthe recording tape cartridge 10. As shown in these drawings, therecording tape cartridge 10 is structured to rotatably accommodate asingle reel 14 in a case 12. The case 12 is substantially rectangular inplan view. A magnetic tape T is wound onto the reel 14. The magnetictape T serves as a recording tape which is an informationrecording/replaying (reading/writing) medium.

The case 12 is structured by matching up and joining two peripheralwalls 16A and 18A of an upper case 16 and a lower case 18 to oneanother. A front-right corner portion of each of the upper case 16 andthe lower case 18, which is a single corner portion at a front end sidein the direction of loading into the drive device, is cut away. Anaccommodation space for the reel 14, onto which the magnetic tape T iswound, is provided inside the case 12. Hence, the cut away cornerportions of the peripheral walls 16A and 18A of the upper case 16 andthe lower case 18 serve as the opening 20 for drawing out the magnetictape T.

A leader pin 22 is connected at a free end of the magnetic tape T thatis drawn out through the opening 20. The leader pin 22 is caught up(engaged) by drawing-out means of the drive device, and subjected to adrawing-out operation. At each of two end portions of the leader pin 22,which protrude beyond width direction end portions of the magnetic tapeT, an annular groove 22A is formed. These annular grooves 22A are caughton to by hooks or the like of the drawing-out means. Consequently, inthis structure, the hooks or the like do not contact and damage themagnetic tape T when the magnetic tape T is drawn out.

At an inner side of the opening 20 of the case 12, a pair of upper andlower pin stands 24 are provided for positioning and retaining theleader pin 22 in the case 12. The pin stands 24 have semi-tubular forms,and both the end portions of the leader pin 22 are held at recessportions 24A of the pin stands 24 in a state in which the leader pin 22is standing thereat. Outer peripheral walls of the pin stands 24 areopen at a magnetic tape T drawing-out side thereof, to form exit/entryapertures through which the leader pin 22 is removed and inserted.

A leaf spring 25 is fixedly disposed in a vicinity of the pin stands 24.The leaf spring 25 engages with upper and lower end portions of theleader pin 22, and holds the leader pin 22 at the pin stands 24. Theleaf spring 25 is structured to resiliently deform appropriately whenthe leader pin 22 is removed or inserted at the pin stands 24, and toallow movements of the leader pin 22.

A gear aperture 26 is formed at a central portion of the lower case 18.The gear aperture 26 is for exposing an unillustrated reel gear of thereel 14 to the outside. The reel gear meshes with a driving gear of thedrive device, and the reel 14 is driven to rotate inside the case 12.Further, the reel 14 is held by free play-restricting walls 28 so as notto rattle about. The free play-restricting walls 28 are providedprojecting at interior surfaces of the upper case 16 and the lower case18, to serve as interior walls partially disposed along a circular pathwhich is coaxial with the gear aperture 26.

A hollow portion 28A is provided continuously with an end portion of thefree play-restricting walls 28 in a vicinity of the opening 20. A holefor regulation of position at an interior is formed in the hollowportion 28A. In addition, a hollow portion 28B is formed continuouslywith the free play-restricting walls 28 at an inner side of a front-leftcorner portion of the case 12. Another hole for regulation of position,which is a long hole, is formed in the hollow portion 28B. The hollowportion 28A and the hollow portion 28B are disposed co-linearly alongthe direction of arrow B. Except for the end portion at which the hollowportion 28A is continuously provided, each of the free play-restrictingwalls 28 is provided continuously with the peripheral wall 16A or theperipheral wall 18A of the case 12. Thus, outer sides of the freeplay-restricting walls 28 and the space for disposing the reel 14 areset apart.

[Structure of Opening and of Case at Opening Vicinity]

As described above, the opening 20 is formed by cutting away thefront-right corner portion. Therefore, an opening face thereof (anangled wall portion) faces in the direction of arrow A and in thedirection of arrow B. Consequently, the drawing-out means of the drivedevice can access and chuck the leader pin 22 from the direction ofarrow A, from the direction of arrow B, or from a direction between thedirections of arrow A and arrow B. As a result, an area in which the pinstands 24 that hold the leader pin 22 can be disposed is large, and arange from which the drawing-out means of the drive device can chuck theleader pin 22 is wide. Accordingly, a disposition position of the pinstands 24 can be specified to meet specifications of drive devices thatcarry out chucking from direction A and drive devices that carry outchucking from direction B. Thus, a degree of freedom of design of thedrive device is broadened.

As is also shown in FIG. 3, which is a plan view of the lower case 18, apair of short upper and lower diagonal wall portions 30 is provided at aright corner portion of a front wall 12A of the case 12 (a portion ofthe peripheral walls 16A and 18A whose outer surface faces in thedirection of arrow A). The diagonal wall portions 30 define a front edgeportion of the opening 20. The diagonal wall portions 30 curve to runalong the opening face of the opening 20, and a wall thickness of thediagonal wall portions 30 is thicker than the front wall 12A. A recessportion 30A is formed at a thickness direction central portion of thediagonal wall portions 30. A distal end of the door 50, which isdescribed later, enters into the recess portion 30A. Further, a pair ofupper and lower screw bosses 32 are provided continuously with an innerside of the front wall 12A in a vicinity of a left end of the diagonalwall portions 30.

A pair of upper and lower offset wall portions 34 is provided at a frontend portion of a right wall 12B of the case 12 (a right side wall of theperipheral walls 16A and 18A along the direction of arrow A). The offsetwall portions 34 are slightly offset to the inside of the case 12(leftward). Front ends of the offset wall portions 34 define a rear edgeof the opening 20. A pair of upper and lower screw bosses 36 is providedcontinuously with an inner side of front end portions of the offset wallportions 34. Outer peripheral portions of the screw bosses 36 functionas a guide for the door 50 which is slidable against the door 50 (toprevent rattling). Further, a pair of upper and lower step portions 38is integrally formed between rear end portions of the offset wallportions 34 and the right wall 12B.

A slit 40 having a predetermined length, which serves as a windowportion communicating between the interior and exterior of the case 12,is formed in the right wall 12B rearward of the offset wall portions 34.The slit 40 is for exposing an operation projection 52 of thebelow-described door 50. The slit 40 is formed by cutting away a lowerportion of the peripheral wall 16A and an upper portion of theperipheral wall 18A, which structure the right wall 12B. By also cuttingaway a lower portion and an upper portion, respectively, of the upperand lower step portions 38, the slit 40 is opened frontward.

The slit 40 may instead be defined from above and below simply by aceiling plate and a floor plate of the case 12. However, in view ofstrength when dropped, it is preferable if portions of the peripheralwalls 16A and 18A are left above and below the slit 40 as describedabove, to function as ribs such that rigidity of the case 12 ismaintained. In particular, the peripheral walls 16A and 18A, which jointhe upper and lower walls that define the slit 40 to one another at bothends thereof, are formed integrally (continuously) with the offset wallportions 34 (the step portions 38), which is even more preferable.

The protrusion portion 42 protrudes from rear end portions of the upperand lower offset wall portions 34, at a side thereof which is oppositeto a side thereof at which the step portions 38 are disposed (that is,inward of the case 12) and is provided to span the whole height of theoffset wall portions 34. A distal surface of the protrusion portion 42is curved to correspond to an outer surface of the later-described door50. In addition, a protrusion portion 44 spanning the whole height isprovided at a location of the free play-restricting walls 28 whichcorresponds to the protrusion portion 42. The protrusion portion 44 iscurved to correspond with an inner face of the door 50, and opposes theprotrusion portion 42.

When the door 50 opens or closes the opening 20, the protrusion portion42 and the protrusion portion 44 are slidable against the door 50 whilesandwiching the door 50. Thus, the protrusion portion 42 and theprotrusion portion 44 are for preventing the ingression of dust into thecase 12, and are for guiding the door 50 (preventing looseness). Afurther protrusion portion 46 protrudes inward of the case 12 at aportion of the right wall 12B (the peripheral walls 16A and 18A) thatdefines a rear end of the slit 40. The protrusion portion 46 is also forpreventing the ingression of dust into the case 12 and guiding the door50 (preventing rattling).

A recess portion 48 is formed rearward of the protrusion portion 46 ofthe lower case 18. The recess portion 48 is recessed toward the insideof the case 12 at a portion of the peripheral wall 18A, which does notinclude an upper end of the peripheral wall 18A, and upward from a lowerface of the case 12, and substantially has a three-sided box shape insectional view. The recess portion 48 is also formed in a left wall ofthe case 12. These recess portions 48 serve as, for example, engagingportions for engaging with the drawing-out means of the drive device,with bottom surfaces of the recess portions 48 (surfaces that facedownward) serving as reference surfaces for positioning in the drivedevice. Furthermore, twisting strength of the case 12 is improved byprovision of the recess portions 48. A portion of the right wall 12B(the peripheral wall 18A) that defines the recess portion 48 is curvedto correspond to the outer surface of the door 50. This guide surface48A serves as a guide for the door 50, and is slideable against theouter surface of the door 50 when the opening 20 is opening or closing(to prevent looseness).

The upper case 16 and the lower case 18 described above are fixed(joined) by unillustrated screws which are screwed from the lower sideinto each of the screw bosses 32 and 36 (joining portions), which arelocated in the vicinities of edge portions of the opening 20.Accordingly, corner portions at both ends of the opening 20, which aredefined by free ends of the diagonal wall portions 30 (the front wall12A) and the offset wall portions 34 (the right wall 12B) and which tendto be severely affected when impacted against a floor or the like by afall, are securely fixed. Thus, even if the case 12 is dropped, thisstructure will not be deformed or buckled by the overall weight of therecording tape cartridge 10, so as to cause mispositioning.

A major diameter across the threads of the screws may be, for example,2.0 mm. Thus, an external diameter of the screw bosses 32 and the screwbosses 36 may be 4.0 mm. In place of this fixing with screws,projections may project from the upper case 16 at positionscorresponding to the screw bosses 32 and 36, while fitting holes whichfit with these projections are formed in the lower case 18, and theprojections and fitting holes may be fitted with one another. However,in such a case, it is desirable that the upper case 16 and the lowercase 18 be fixed with screws at locations within radii of 30 mm of thesefitting locations. Further, matching surfaces of the peripheral wall 16Aand the peripheral wall 18A (at both side corner portions of the opening20) may be fixed by welding. However, fixing with screws is morepreferable in consideration of dismantling and recycling.

Plate thicknesses of both the upper case 16 and the lower case 18 areset to 2 mm at the area in which the pin stands 24 are disposed (thevicinity of the opening 20), which is thicker than thicknesses at otherareas thereof. The case 12 (the upper case 16 and the lower case 18) isformed of a polycarbonate (PC) material. The case 12 may be formed ofacrilonitrile butadiene styrene (ABS) or a metal instead of PC. Thepurpose of this is to raise the strength of the vicinity of the pinstands 24, which is the location at which the leader pin 22 is held(positioned). Therefore, mispositioning of the leader pin 22, which isthe most important component for functioning of the recording tapecartridge 10 (and which must be accurately engaged by the drawing-outmeans when the recording tape is to be drawn out), subsequent to impactsdue to dropping of the case 12 (the recording tape cartridge 10) or thelike does not occur.

Positions at which the pin stands 24 are disposed are determined suchthat an axial center of the leader pin 22 held thereat is positioned onan imaginary line which joins the front and rear edge portions of theopening 20, or further inside the case 12 than this imaginary line. Thepositions at which the pin stands 24 are disposed are more preferablydetermined such that the axial center of the leader pin 22 is positionedon an imaginary line K which joins axial centers of the screw bosses 32and the screw bosses 36, or further inside the case 12 than thisimaginary line K, and are even more preferably determined such that theaxial center of the leader pin 22 is positioned not at a vertical line Hthat equally bisects the imaginary line K, but at a side of either thescrew bosses 32 or at a side of the screw bosses 36. Incidentally, theunillustrated pin stand 24 is disposed at a position upward of the door50, and closer to the screw bosses 32 than to the screw bosses 36.

Consequently, with this structure, mispositioning of the leader pin 22due to vibrations of the ceiling plate and the floor plate thataccompany dropping of the case 12 or the like are prevented.Specifically, as shown in FIG. 7, this position is a position whichavoids a location at which an amount of vertical warping due tovibrations applied to the case 12 is large (an anti-node of vibrationamplitude). Thus, the closer this position is to the screw bosses 32 or36, the smaller the amount of warping (vibration amplitude isattenuated). Accordingly, if the pin stands 24 are disposed at such aposition (near a node of vibration amplitude), resistance to an impactapplied to the vicinity of the opening 20 is strengthened, anddisplacement of the leader pin 22 from the pin stands 24, or detachmenttherefrom, will not occur.

In this case 12, the peripheral wall 16A of the upper case 16 and theperipheral wall 18A of the lower case 18 are set to equal heights. Thus,machining accuracies of portions thereof that match up with one another(accuracies of resin-forming in molds) are at about the same level.Thus, assembly characteristics and dropping impact resistance are madefavorable.

A diagonal angle of the opening face of the opening 20 with respect tothe direction of arrow A (a diagonal angle of the ceiling plate andfloor plate of the case 12 that define the top and bottom of the opening20) is determined in accordance with requirements for distinguishing(identifying) the recording tape cartridge 10 at a library apparatus.That is, the library apparatus accommodates a plurality of the recordingtape cartridge 10 and automatically (i.e., without human intermediation)mounts and removes the recording tape cartridge 10 at the drive device.In a case where there is a plurality of types of the recording tapecartridge 10 to be handled and a plurality of types of drive device, itis necessary to identify a generation, recording capacity or the like ofthe recording tape cartridge 10. The diagonal angle of the opening faceof the opening 20 may be utilized for this identification.

Accordingly, the opening 20 for drawing out of the magnetic tape T,which has been implemented in consideration of strength as describedabove, can also function as an identification portion in a libraryapparatus, based on the diagonal angle of the opening face of theopening 20 (to be specific, the diagonal angle of the ceiling plate andfloor plate that define the top and bottom of the opening 20).Therefore, insufficient strength of the case 12, a deterioration ofdustproofing and complicated mold construction, which are concerns in asituation in which the opening 20 and the identification portion areprovided separately (for example, a case in which one or a plurality ofthrough-holes formed in the case 12 serve as an identification portion),can be prevented.

[Door Structure]

As shown in FIGS. 4 and 5, which are viewed with the reel 14, the uppercase 16 and the like removed, the opening 20 is opened and closed by thedoor 50, which serves as a covering member. The door 50 is formed in acircular arc form in plan view, which is curved in a plate thicknessdirection along a predetermined circular circumference, with a platewidth (height) of the door 50 set to be substantially the same as anopening height of the opening 20, and a plate length thereof beingsignificantly greater than an opening width of the opening 20.

Specifically, in this structure, in a state in which the door 50 hasentered into the recess portion 30A of the diagonal wall portions 30 (aclosed position), the door 50 closes the opening 20 (see FIG. 6A). Thedoor 50 opens the opening 20 by moving (rotating) substantially rearwardalong the aforementioned circular circumference, (see FIG. 6B). When anouter peripheral surface of a distal end vicinity of the door 50 reachesa vicinity of the screw bosses 36, the opening 20 is completely opened(an open position; see FIG. 6C). When the opening 20 is open, the door50 closes the opening 20 by rotating substantially in the oppositedirection. In the closed state of the opening 20, the door 50 abutsagainst at least one of the screw bosses 36, the protrusion portion 42and the protrusion portion 44.

That is, the door 50 is formed to be curved in an arc shapecorresponding to the predetermined circular circumference, which is amovement path of the door 50. In the present embodiment, a position of acenter of rotation of the door 50 in a left-right direction is specifiedto be at a left end vicinity of the case 12, and a position thereof in afront-rear direction is specified to be at a vicinity of the rear end ofthe slit 40. Consequently, the movement path of the door 50 is closestto the right wall 12B of the case 12 in the vicinity of the rear end ofthe slit 40. The rotation center and a turning radius of the door 50 maybe suitably determined in accordance with the positions of the front andrear edge portions of the opening 20 (the diagonal wall portions 30 andthe screw bosses 36). These positions are determined by requirements ofthe drive device, in accordance with the angle of the facing surface ofthe opening 20, which is determined by requirements of a libraryapparatus, and the like.

A rear end portion of a length dimension along the curve of the door 50is determined so as to be located at a rear-right corner portion, whichis rearward of the recess portion 48 of the case 12, in the state inwhich the opening 20 is closed. Accordingly, all through the process ofopening and closing the opening 20, the door 50 is guided (loosenessthereof is restrained) by the screw bosses 36, the protrusion portions42, 44 and 46, and the guide surface 48A (and the free play-restrictingwalls 28) of the case 12.

At an outer peripheral surface of the door 50, slightly forward from alength direction central portion thereof, the operation projection 52projects along a diametric direction of the door 50, to serve as anoperation portion. The operation projection 52 is exposed to the outsideof the case 12 through the slit 40. When the opening 20 is in the closedstate, the operation projection 52 is positioned to be slightlyseparated from the protrusion portion 42 at the rear end of the offsetwall portions 34, and is operable through the portion of the slit 40that opens frontward at the step portions 38.

When the opening 20 is in the opened state, the operation projection 52is positioned to be slightly separated from the protrusion portion 46 atthe rear edge of the slit 40. The dimensions of each portion aredetermined such that a length direction of the operation projection 52is substantially perpendicular to the right wall 12B of the case 12 (thedirection of arrow A) in this state.

Thus, although this operation projection 52 communicates between theinterior and exterior of the case 12 via the slit for exposure, the slit40 is always substantially closed by the door 50, which spanssubstantially the whole height of the interior of the case 12, and bythe protrusion portion 42 and protrusion portion 46 which guide the door50. In addition, a labyrinthine structure is formed between the slit 40and the accommodation space for the reel 14 by the free play-restrictingwalls 28 which serve as inner walls and the protrusion portion 44 whichguides the door 50. Accordingly, adherence of dust and the like to themagnetic tape T wound onto the reel 14 is prevented.

A spring-holding portion 54 protrudes along the diametric direction ofthe door 50 from an interior peripheral portion at a rear end vicinityof the door 50. One end portion of a coil spring 56, which serves asurging means (an urging element), is engaged with a spring-engagingportion 55, which is provided inside the case 12 at a vicinity of therecess portion 48. Another end portion of the coil spring 56 is engagedand held at the spring-holding portion 54. Accordingly, in thisstructure, the door 50 is urged in a direction to close the opening 20by urging force of the coil spring 56, and the door 50 continuouslycloses the opening 20. The coil spring 56 has a length that reaches asfar as the rear-right corner portion of the case 12 in the state inwhich the door 50 opens the opening 20 as described above. Thus, thecoil spring 56 is disposed so as to effectively use a space between thefree play-restricting walls 28 and the peripheral walls 16A and 18A atthe rear-right corner portion.

The door 50 described hereinabove is formed of, for example, apolyoxymethylene (POM) resin, which has a low coefficient of frictionand has excellent abrasion resistance with respect to the case 12constituted of PC. The operation projection 52, the spring-holdingportion 54 and the like may be structured as separate bodies (ofdifferent materials). Thus, because operation of the door 50 can becarried out smoothly, it is preferable if clearances between endsurfaces at the top and bottom of the door 50 and the ceiling plate andfloor plate of the 12 are set to the order of 0.05 mm to 0.2 mm each.

Next, operation of the recording tape cartridge 10 having the structuredescribed above will be described. The opening 20 of the recording tapecartridge 10 is closed by the door 50 when the recording tape cartridge10 is not in use (during storage, during transportation, and the like).Specifically, a distal end portion (front end portion) of the door 50 isentered into the recess portion 30A of the diagonal wall portions 30 bythe urging force of the coil spring 56. At the same time, anintermediate portion outer peripheral surface of the door 50 abutsagainst the outer peripheral surface of the screw bosses 36 to close theopening 20.

In contrast, when the magnetic tape T is to be used, the recording tapecartridge 10 is loaded into the bucket 60 of the drive device along thedirection of arrow A. In accordance with this loading, as shown in FIG.6A, the engaging protrusion 60, which serves as the opening memberstructuring opening means of the drive device, advances into the slit 40which opens frontward at the step portions 38, and engages with theoperation projection 52 of the door 50.

As the recording tape cartridge 10 (the case 12) is pushed in further,the urging force of the coil spring 56 is opposed by a force of pushingin and, as shown in FIG. 6B, the engaging protrusion 60 moves theoperation projection 52 rearward (that is, relatively rearward withrespect to the case 12 which is being loaded in the direction of arrowA). Thus, the door 50 from which the operation projection 52 protrudesis guided by the screw bosses 36, the protrusion portions 42, 44 and 46,and the guide surface 48A. At the same time, the door 50 rotatesclockwise, in plan view, along the direction of curvature thereof.

That is, the door 50 moves substantially rearward so as to swing at theouter side of the reel 14 and the pin stands 24 without significantlydeviating from the movement path along the shape of the curvature, andthe door 50 opens the opening 20. Thus, when the case 12 (the recordingtape cartridge 10) is loaded to a predetermined depth in the drivedevice, the opening 20 is completely opened, as shown in FIG. 6C. Inthis state, the recording tape cartridge 10 is positioned in the drivedevice, and further rotation of the door 50 (substantially rearwardmovement thereof) is restricted.

In this state, the recording tape cartridge 10 is positioned within thedrive device. Then, the drawing-out means of the drive device advancesinto the case 12 through the opened opening 20, and the drawing-outmeans takes out the leader pin 22, which has been positioned andaccommodated at the pin stands 24, and accommodates the leader pin 22 atthe winding reel. Then, the winding reel and the reel 14 are driven torotate at the same time, and the magnetic tape T is wound around thewinding reel while being sequentially drawn out from the case 12.Information recording/replaying is carried out on the magnetic tape T bythe recording/replaying head or the like which is disposed along thepredetermined tape path.

Subsequently, when the magnetic tape T has been wound back to the reel14 again, the recording tape cartridge 10 is ejected from the drivedevice. At this time, the state of positioning of the recording tapecartridge 10 is released, and the recording tape cartridge 10 is movedin a direction opposite to the direction of arrow A by the urging forceof the coil spring 56 and/or by an unillustrated ejection mechanism.Thus, the door 50 is guided by the screw bosses 36, the protrusionportions 42, 44 and 46, and the guide surface 48A, while being rotatedin the closing direction of the opening 20 by the urging force of thecoil spring 56. The distal end portion of the door 50 enters into therecess portion 30A of the diagonal wall portions 30, and the door 50returns to the initial state in which the opening 20 is completelyclosed.

Here, because the opening 20 is formed by cutting away the loading sidecorner portion of the rectangular case 12, the opening face of theopening 20 faces in the direction of arrow A and in the direction ofarrow B (the facing angle is diagonal with respect to the direction ofarrow A). This means that the drawing-out means of the drive device cangain access to the leader pin 22 from a front face side which faces thecase 12 in the direction of arrow A, and it is not required that thedrawing-out means gain access from a side that is outside of the arrow Bside peripheral walls (side walls) 16A and 18A (i.e., from an arrow Bside). Consequently, in this drive device, a path for drawing out themagnetic tape T can be made as short as possible, and the drawing-outmeans does not require a drive mechanism for turning the magnetic tape Taround from the arrow B side of the case 12. Thus, a reduction in sizeand cost reductions can be expected.

Further, the door 50, which is curvedly formed in the circular arcshape, is rotated to open and close the opening 20 by swinging around anouter side of the reel 14 and the pin stands 24 (and the leader pin 22)without deviating from the movement path along the shape of thecurvature. Therefore, the door 50 will not protrude beyond an externalprofile region of the case 12 during opening and closing of the opening20. Consequently, a space for accommodation of the recording tapecartridge 10 in the drive device is small, and the movement path of thedoor 50 does not interfere with the pin stands 24 (the leader pin 22),the reel 14 and the like in the case 12.

Further yet, it is sufficient that the engaging protrusion 60 of thedrive device be fixedly disposed to be engageable with the operationprojection 52 of the door 50 simply by advancing into the slit 40 fromthe front side thereof. Thus, construction is simple. Further again,because the door 50 closes the opening 20 due to the urging force of thecoil spring 56, a drive device side mechanism for driving the door 50 inthe direction of closing the opening 20 is not required. Thus,construction of the opening/closing means (opening/closing member) ofthe drive device is made more simple.

Accordingly, with the recording tape cartridge 10 as described above,the door 50, which can make a space for accommodating the recording tapecartridge 10 at the drive device smaller, can open and close the opening20, whose structure can minimize length of the drawing-out path of themagnetic tape T, without the door 50 interfering with the reel 14 andthe leader pin 22. Moreover, the engaging protrusion 60, which serves asthe opening means (opening member) for operating the door 50 to open andclose the opening 20, can be given a simple structure.

Because the movement path of the door 50 as described above is acircular circumference (a curvilinear shape), the corner portion of thecase 12 can be greatly cut away, and the opening 20 can be formed to belarge. That is, in a case in which, for example, a flat plate-formcovering member is inclined relative to the direction of arrow A, thiscovering member will be accommodated in an exterior profile region ofthe case 12. In this situation, an operation area that is required forchanging the attitude of the covering member by linear displacement orrotary displacement to open and close the opening 20 will be greater,and the opening 20 will have to be made smaller (the cutaway portion ofthe corner portion of the case 12 that forms the opening 20 will have tobe made smaller) such that the operation of the covering member does notinterfere with the leader pin 22, the reel 14 and the like. However,with the recording tape cartridge 10 relating to the present embodiment,because the door 50 which opens and closes the opening 20 by turning onthe predetermined circular arc without deviating therefrom as describedabove is provided, an increase in size of the opening 20 can be enabled.

In particular, a center of rotation of the door 50 for opening andclosing the opening 20, whose opening face is diagonal with respect tothe direction of arrow A, can be determined independently of theposition of an axial center of the reel 14. Therefore, the angle ofinclination of the opening face of the opening 20 relative to thedirection of arrow A, the size of the opening 20 (a separation betweenfront and rear edge portions thereof), and the like can be freelyspecified. Thus, the door 50 can be provided for opening and closing theopening 20, with the opening 20 having dimensions and shape freelyselected in accordance with requirements of the drive device and thelike. That is, with the structure in which the door 50 is provided, adegree of freedom of design of the opening 20 (and thus the recordingtape cartridge 10) is improved.

Further, when the length of the path for drawing out the magnetic tape Tis minimized as described above, a running path of the magnetic tape Twill inevitably be shortened too. As a result, contact friction of themagnetic tape T with tape guides (for example, rotatably supportedrollers and the like) can be reduced. Furthermore, the opening 20 isformed by cutting away the corner portion of the case 12, and faces inthe direction of arrow A and in the direction of arrow B. Thus, a rangeof directions of access to the leader pin 22 by the drawing-out means(by hooks thereof or the like) is widened. Therefore, positions at whichthe leader pin 22 can be disposed in the case 12 are broadened.Therefore, given that the operation path of the door 50 as describedabove must not interfere with positions at which the leader pin 22 canbe disposed in practice, a degree of freedom of design of the drivedevice is improved.

Further again, because the door 50 is a separate member from the leaderpin 22 that is drawn out from the case 12, in this structure the door 50cannot be taken out from the case 12 in an assembled state. Thus, thedoor 50 will not be removed from the case 12 by an impact when therecording tape cartridge 10 is dropped or the like. Moreover, the leaderpin 22 is accommodated in the case 12 in a firmly shut state when theopening 20 has been closed by the door 50 at a time of non-use. Thus,the leader pin 22 is less likely to become damaged or soiled.Consequently, drawing out and running the magnetic tape T at the drivedevice will not affect the drive device, and the magnetic tape T itselfwill not suffer from damage.

The recording tape cartridge 10 relating to the present invention hasthe structure described above. Variant examples of a door mechanismthereof, which differ therefrom, will now be briefly described on thebasis of FIGS. 8A to 11B. In recording tape cartridges of these variantexamples, the pin stands 24 for the leader pin 22 are provided at thesame positions as described above. Firstly, a door 70 shown in FIGS. 8Aand 8B is formed in a substantially circular arc form in plan view,similarly to the above descriptions. Three projections 72 are providedat each of an upper face and a lower face of the door 70. Guide channels74, which have a substantially circular arc form in plan view, areformed in the upper case 16 and the lower case 18, from a vicinity ofthe right wall 12B to a vicinity of a guide rib 75. From a vicinity ofthe guide rib 75 to a vicinity of the left wall 12C, a guide channel 74is formed in the upper case 16 and a guide hole 76 is formed in thelower case 18. One of the projections 72 protrudes out through the guidehole 76. The door 70 is urged in a direction to close the opening 20 bya leaf spring 78.

Accordingly, when the door 70 is to be opened, a drive device sideopening/closing member (not shown) is engaged with the projection 72that protrudes out through the guide hole 76, and pushes that projection72 rearward. Consequently, the door 70 rotates leftward along the guidechannels 74 against urging force of the leaf spring 78, and isaccommodated at an inner side of the front wall 12A, thus opening theopening 20. In this case, because the door 70 is accommodated at thefront wall 12A side, the pin stands 24 are provided at positions whichare inward relative to the imaginary line K that joins the centers ofthe screw bosses 32 and 36 at the two sides of the opening 20, and notat the line H that bisects the imaginary line K but closer to the screwbosses 36 at the right wall 12B side thereof.

A door 80 shown in FIGS. 9A and 9B is hinged at a connecting arm 84,which is connected with a support shaft 82. Projections 83 areprotrudingly provided at lower faces of the support shaft 82, theconnecting arm 84 and the door 80, and at an upper face of the door 80.First guide channels 86 are formed in the upper case 16 and the lowercase 18, and a second guide channel 87 is formed in the lower case 18and communicates with the first guide channel 86 thereof. Accordingly,when this door 80 is to be opened, a drive device side opening/closingmember (not shown) is engaged with a rotation lever 88 which ishorizontally provided at an upper portion of the support shaft 82, andpushes the rotation lever 88 leftward and rearward.

Consequently, the support shaft 82 rotates leftward, and the connectingarm 84 moves leftward along the second guide channel 87 against urgingforce of a torsion spring 89. Thus, the door 80 moves leftward along thefirst guide channel 86, and opens the opening 20. In this case too, thedoor 80 is accommodated at the front wall 12A side, and therefore thepin stands 24 are provided at positions which are inward relative to theimaginary line K that joins the centers of the screw bosses 32 and 36 atthe two sides of the opening 20, and not at the line H that bisects theimaginary line K but closer to the screw bosses 36 at the right wall 12Bside thereof.

A door 90 shown in FIGS. 10A and 10B is formed in a flat rectangularplate shape. A pair of upper and lower guide pins 92 are protrudinglyprovided at one end portion in a longitudinal direction of the door 90,and a pair of upper and lower guide pins 93 are protrudingly provided atanother end portion in the longitudinal direction of the door 90. Anabutting portion 91, which is triangular in plan view, extends outwardat an outer surface of the end portion of the door 90 that is at theside thereof at which the guide pins 92 are provided. A spring-loadedchannel 94 is formed in an inner face of a central portion of the door90. A pair of upper and lower first guide channels 95, into which theguide pins 92 are inserted, and a pair of upper and lower second guidechannels 96, into which the guide pins 93 are inserted, are formed inthe upper case 16 and the lower case 18. The door 90 is urged in adirection to close the opening 20 by a leaf spring 98.

That is, in a state in which the guide pins 93 are located at front endsof the second guide channels 96 and the guide pins 92 are located atfront ends of the first guide channels 95, the one end portion of thedoor 90 abuts against the screw bosses 32 at the front wall 12A side,and the other end portion of the door 90 abuts against the right wall12B in a vicinity of the first guide channels 95. Thus, the opening 20is closed from an inner side thereof. At this time, one end portion ofthe leaf spring 98 is engaged with the spring-loaded channel 94 of thedoor 90, and another end portion of the leaf spring 98 is anchored at ananchoring portion 97, which is provided protruding from an inner face ofthe lower case 18. The door 90 is located at a position to close theopening 20 by urging force of the leaf spring 98.

When the door 90 is to be opened, the abutting portion 91 is movedrearward by a drive device side opening/closing member (not shown).Consequently, the guide pins 92 and 93 move rearward, guided by thefirst guide channels 95 and the second guide channels 96, respectively.When the guide pins 93 are located at rear ends of the second guidechannels 96 and the guide pins 92 are located at rear ends of the firstguide channels 95, the door 90 is lined up substantially parallel withthe right door 12B, and is accommodated at an inner side of the rightwall 12B. Thus, the opening 20 is opened. In this case, because the door90 is accommodated at the right wall 12B side, the pin stands 24 areprovided at positions which are inward relative to the imaginary line Kthat joins the centers of the screw bosses 32 and 36 at the two sides ofthe opening 20, and not at the line H that bisects the imaginary line Kbut closer to the screw bosses 32 at the front wall 12A side thereof.

A door 100 shown in FIGS. 11A and 11B is formed in a flat rectangularplate shape. A pair of upper and lower guide pins 102 are protrudinglyprovided at one end portion in a longitudinal direction of the door 100,and a pair of upper and lower guide pins 103 are protrudingly providedat another end portion in the longitudinal direction of the door 100. Anoperation portion 104, which engages with an opening/closing member of adrive device (not shown), extends outward at an outer surface of the endportion of the door 100 that is at the side thereof at which the guidepins 103 are provided.

Second guide channels 107, into which the guide pins 103 are inserted,are formed in the upper case 16 and the lower case 18, and a first guidechannel 106, into which the guide pin 102 is inserted, is formed in theupper case 16. The first guide channel 106 is curved in a shape whichprotrudes to the outer side of the opening 20. In a state in which theguide pin 102 is located at a front end of the first guide channel 106and the guide pins 103 are located at front ends of the second guidechannels 107, the one end portion of the door 100 abuts against a freeend portion of an angled side wall 109, and the other end portion of thedoor 100 abuts against a stopper 108. Thus, the opening 20 is closedfrom an outer side thereof.

Accordingly, when the door 100 is to be opened, the operation portion104 is moved rearward by the opening/closing member of the drive device(not shown). Consequently, the guide pins 102 and 103 are guided by thefirst guide channel 106 and the second guide channels 107, respectively,and slidingly move rearward in between the angled side wall 109 and thescrew bosses 36. When the guide pin 102 is located at a rear end of thefirst guide channel 106, and the guide pins 103 are located at rear endsof the second guide channels 107, the door 100 is lined up substantiallyparallel with the angled side wall 109, and is accommodated at an outerside thereof. Thus, the opening 20 is opened. In this case too, becausethe door 100 is accommodated at the right wall 12B side, the pin stands24 are provided at positions which are inward relative to the imaginaryline K that joins the centers of the screw bosses 32 and 36 at the twosides of the opening 20, and not at the line H that bisects theimaginary line K but closer to the screw bosses 32 at the front wall 12Aside thereof.

According to the present invention in any of the above, an openingaperture is formed by cutting away a corner portion at the side ofloading a case into a drive device. Therefore, an opening face of thisopening aperture can be faced toward the drive device, and drive deviceside drawing-out means can be advanced into the opening aperture fromthe front side thereof. Thus, a drawing-out path of the recording tapecan be minimized in length. As a result, a complicated mechanism forturning and guiding the recording tape at the drive device is notrequired, and the drive device can be designed to be compact, with lowproduction costs.

Furthermore, because a position at which a holding portion which holds aleader pin is provided is at a position at which an amount of warpingdue to an impact is extremely small, mispositioning or detachment of theleader pin from the holding portion when the opening aperture vicinityis subjected to an impact, when the cartridge is dropped or the like,can be prevented.

1. A tape cartridge which is insertable at a tape drive which carriesout at least one of reading and writing of data, the tape cartridgecomprising: a case which includes a front wall portion facing in adirection of insertion of the cartridge, a side wall portionsubstantially parallel to the cartridge insertion direction, and anangled wall portion connected with the front wall portion and the sidewall portion and angled relative to the cartridge insertion direction,the case being structured by joining an upper case and a lower case at aplurality of joining portions; an openable and closeable tape accessopening provided at the angled wall portion of the case; and a leaderpin attached to a tape end, the leader pin being detachably held so asto be substantially vertical at a position which is on or at an innerside of a line from one to another of joining portions that are providedat vicinities of end portions, in plan view, of the tape access opening,wherein the joining portions are fixed by screws.
 2. The tape cartridgeof claim 1, further comprising a pin-holding structure which detachablyholds the leader pin at each side in a longitudinal direction of theleader pin.
 3. The tape cartridge of claim 2, wherein the pin-holdingstructure comprises a pair of substantially semi-tubular pin stands anda leaf spring.
 4. The tape cartridge of claim 2, wherein the pin-holdingstructure is located at a side of the joining portion that is closer tothe side wall portion than a line which vertically bisects the line fromone to the other of the joining portions.
 5. The tape cartridge of claim1, further comprising a covering member which is reciprocally moveablealong a circular arc-form movement path between a closed position forclosing the tape access opening and an open position for opening thetape access opening.
 6. The tape cartridge of claim 5, furthercomprising a pin-holding structure which detachably holds the leader pinat each side in a longitudinal direction of the leader pin.
 7. The tapecartridge of claim 6, wherein the pin-holding structure is located at aside of the joining portion that is closer to the side wall portion thana line which vertically bisects the line from one to the other of thejoining portions.
 8. The tape cartridge of claim 7, wherein the joiningportions are fixed by screws.
 9. The tape cartridge of claim 5, furthercomprising a slide guidance portion disposed along the circular arc-formmovement path and at least one of line-contacting and surface-contactingthe covering member for dustproofing.
 10. The tape cartridge of claim 5,further comprising an urging element which continuously urges thecovering member in a closed position direction.
 11. The tape cartridgeof claim 5, wherein the covering member comprises an operation portioncapable of moving the covering member in an open position direction whenengaged with the tape drive by an operation of insertion of the tapecartridge.
 12. The tape cartridge of claim 11, further comprising awindow portion provided at the side wall portion of the case, whichwindow portion allows relative engagement of the tape drive with theoperation member at a time of insertion of the tape cartridge.
 13. Thetape cartridge of claim 12, wherein the window portion comprisesstructure such that the window portion does not physically interferewith the tape drive and the operation member at the time of insertion ofthe tape cartridge, and the window portion comprises a long, narrow slitextending along the cartridge insertion direction.
 14. The tapecartridge of claim 12, further comprising a wall portion forreinforcement between the window portion and the tape access opening,which makes the window portion and the tape access openingnon-continuous with one another.
 15. The tape cartridge of claim 5,further comprising a reel at which a tape is wound, the reel beingaccommodated in the case such that the tape can be drawn out through thetape access opening.
 16. The tape cartridge of claim 15, furthercomprising a partition wall portion disposed between the reel and thecircular arc-form movement path.
 17. The tape cartridge of claim 16,wherein the partition wall portion comprises a part-cylindrical formwhich is substantially concentric with the reel.
 18. The tape cartridgeof claim 1, wherein the case appears substantially rectangular in planview.
 19. The tape cartridge of claim 5, wherein the case is formed of aresin, and the covering member is formed of an abrasion-resistant resinwhich is different from the resin of the case.